@bruhmomentummoment: When a fingernail takes a direct impact hard enough to cause bruising, blood pools in the tissue between the nail and the nail bed, which is what causes the nail to turn black. The pressure from that pooled blood is also what causes the nail to separate from the bed over time as the tissue beneath it swells and pushes upward. The new nail begins growing from the nail matrix, the tissue at the base of the finger, immediately after the injury occurs, which is what eventually forces the damaged nail off entirely. Full nail regrowth typically takes three to six months depending on the severity of the injury, with the nail often appearing ridged or misshapen in the early stages before flattening out as it extends past the nail bed. #science #biology #health #satisfying #nature